1. Technical Field
The present invention relates to a rotary-member control apparatus.
2. Related Art
As a rotary-member control apparatus controlling a rotary member that is rotatable while supporting an object on the outer curved surface of the member, there is known a liquid discharge apparatus (e.g., an ink jet printer) that includes a rotary member and discharges ink, serving as a liquid, onto a medium, serving as an example of the object supported, to print an image.
JP-A-10-193582 discloses such a printer. The printer further includes a discharging unit that discharges ink onto a medium supported on the rotary member. During rotation of the rotary member supporting the medium, the discharging unit discharges ink, so that an image is printed. The printer further has a motor that rotates the rotary member. The motor is supplied with current based on a current profile, representing the magnitude pattern of current, to rotate the rotary member.
Assuming that the rotary member has a structure in which the rotary member rotates while supporting a medium, in some cases, the rotary member becomes eccentric. In particular, when media have various lengths, the degree of eccentricity tends to vary depending on the length. If the rotary member is eccentric, the rotational speed of the rotary member easily fluctuates during rotation, so that rotational variation occurs.